Conventionally, fluorine resin has been used in the form of lamination or coating on the surface layer of a sliding member due to its low coefficient of friction. When fluorine resin is laminated or coated, however, a fluorine resin film is thin and easy to peel off because of its non-adhesion property and therefore laminating or coating has to be repeated to keep the long-term sliding property. To solve such a drawback, a sliding member has been developed, including fluorine resin in the form of fibers arranged as a woven or knitted fabric or a non-woven fabric on the surface of the sliding member to improve its friction durability, which is then made into a composite member with a woven or knitted fabric of an easily-adhering nature with other materials for firmer adhesion.
For example, JP H01-98921 U discloses a technique for a bearing structure made up of a supporter and a sliding part, which is made by coating the surface of the sliding part with a fiber cloth having PTFE-based fibers with single fiber fineness of 3.5 d or less at least at the surface of the bearing structure so that the bearing structure has an excellent easy sliding property.
JP 2008-150724 A discloses a multilayer structured cloth to reduce friction of vibration-absorbing rubber in a stabilizer bar of an automobile, including fluorine-based fibers on one surface and thermal adhesiveness fibers on the other surface to improve adhesiveness between the cloth and the sliding face of the vibration-absorbing rubber. JP 2009-35827 A discloses a technique for a cloth including fluorine-based fibers on one surface and dipped yarns prepared by coating fibers other than the fluorine-based fibers with resin beforehand to improve adhesiveness with rubber.
JP 2011-42413 A discloses a moving handrail of a conveyor, including a resin body part having a C-letter shape in cross section and is endless, and canvas disposed along the longitudinal direction of the resin body part and on an inside of the resin body part, and this canvas includes a base cloth disposed at the resin body part and a fluorine-fiber sliding cloth disposed on the base cloth to cover the surface of the base cloth partially, the fluorine-fiber sliding cloth having friction characteristics lower than those of the base cloth.
JP 2008-45722 A discloses a base isolating device including a lower shoe having a lower load-receiving face of a circular arc concave shape in cross section and an upper shoe having an upper load-receiving face of a circular arc concave shape in cross section, and a sliding body interposed between the lower load-receiving face of the lower shoe and the upper load-receiving face of the upper shoe and having a face at each of a top face and a bottom face thereof of a circular arc convex shape in cross section that comes into face-contact with each of the upper load-receiving face and the lower load-receiving face. In this base isolating device, the sliding body includes: a base made up of the lamination of thermosetting synthetic resin that is reinforced with fiber woven cloth, and a composite woven cloth sheet including a composite woven cloth made up of a woven cloth made of tetrafluoroethylene resin fibers and a woven cloth of organic fibers mutually overlapped and sewn with yarns made of fluorine resin for integration and thermosetting synthetic resin applied to the composite woven cloth for impregnation. On the organic fiber woven cloth side of the composite woven cloth sheet, surface-layer members joined integrally with the upper face and the lower face of the base, at least one concave formed on the base and these surface-layer members to be open at the surface of the surface-layer members serving as the cross-sectional circular arc convex face of the sliding body and to extend to a part of the base, and solid lubricant charged and held in a part surrounded with the surface-layer members and a part surrounded with the base continuous to the part of the concave are included.
However, the fiber cloth described in JP '921 as stated above is a cloth made up of yarns obtained by mix-spinning, intertwisting or twisting PTFE-based fibers and other fibers, a pile cloth including a typical synthetic fiber cloth as a base cloth and PTFE-based fibers as piles, or a cloth prepared by electrically flocking of the base cloth. In the cloth made up of yarns obtained by mix-spinning, intertwisting or twisting PTFE-based fibers and other fibers as stated above, fluorine fibers worn down are accumulated at gaps between fibers. The space for the accumulation, however, is small, so that the worn-down fluorine fibers will be discharged to the outside of the system. It thus is difficult to greatly improve durability. In the latter clothes including fluorine fibers at the surface layer as piles or prepared by flocking, confinement of fluorine fibers is loose, and the cloth will be easily worn.
When the cloth specifically described in JP '724 and JP '827 is used for a sliding purpose under high-load environment, fluorine fibers move easily, and damage to the fluorine fibers increases with an increase in the sliding distance so that the coefficient of friction increases or the durability decreases easily, and the durability will be degraded with an increase in load applied.
The technique described in JP '413 is to lengthen the life of a conveyor by decreasing friction during movement, and fix the canvas on the inside of the man conveyor and the sliding cloth easily and reliably while assuming sliding under low load applied to the conveyor. The durability thereof becomes extremely low when high load is applied. In the structure described in JP 722, sewing with the woven cloth made of organic fibers for integration is performed to improve adhesiveness of the lamination of thermosetting synthetic resin reinforced with fiber woven cloth as the base and the tetrafluoroethylene resin fibers. Thus, the manufacturing steps are complicated.
It could therefore be helpful to provide a wear-resistant cloth having high wear resistance and capable of exerting a long-term sliding property even under high-load environment as compared to conventional cloths.